<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .outer {
            width: 1000px;
            height: 500px;
            border: 1px solid #000;
            display: flex;
            /* flex-direction: column; */
        }

        .outer div:nth-child(1) {
            background-color: pink;
            flex-grow: 1;
            /* width: 0; */
            /* height: 0; */
            flex-basis: 0;
            flex-shrink: 1;

            flex: 1;
        }

        .outer div:nth-child(2) {
            background-color: yellowgreen;
            flex-grow: 1;
            /* width: 0; */
            /* height: 0; */
            flex-basis: 0;
            flex-shrink: 1;
        }

        .outer div:nth-child(3) {
            background-color: greenyellow;
            flex-grow: 1;
            /* width: 0; */
            /* height: 0; */
            flex-basis: 0;
            flex-shrink: 1;
        }
    </style>
</head>

<body>
    <div class="outer">
        <div>hello <br>123</div>
        <div>nice</div>
        <div>ddddddd</div>
    </div>
</body>

</html>